An acute aortic dissection is a separation of the inner and outer layers of the aortic wall. This results in two separate channels of blood forming within the aorta. This condition represents an emergency situation and requires prompt evaluation and treatment.

Aortic dissection is relatively uncommon. It usually occurs in men in their 60s and 70s. Symptoms of aortic dissection may mimic those of other diseases, often leading to delays in diagnosis. However, when an aortic dissection is detected early and treated promptly, the chance of survival greatly improves.

There are two main types:

• Stanford Type A Aortic Dissection: This type of dissection occurs in the first part of the aorta, closer to the heart, and can be immediately life-threatening. It usually requires emergency open chest surgery to repair or replace the first segment of the aorta where the tear started (ascending aorta +/- the arch and/or aortic valve). This is a more common type of dissection than Type B, and the dissection of the aorta usually extends through the entire length of the aorta.
• Stanford Type B Aortic Dissection: This type of tear begins farther down the aorta (descending aorta beyond the arch), and farther from the heart. Like the type A dissection, this usually extends from the descending aorta into the abdominal segment (abdominal aorta), but doesn’t involve the first part of the aorta in the front of the chest. Surgery may or may not be needed immediately, depending on exactly where the dissection is located and if it is or isn’t cutting off blood flow to your organs. These operations usually can be performed with a stent-graft device inserted into the aorta.

Another classification system (DeBakey Classification) defines dissection by three types. Type 1 originates in the ascending aorta and extends through the downstream aorta. Type 2 originates and is limited to the ascending aorta (both would be considered Stanford Type A). Type 3 originates in the descending aorta and extends downward (similar to Type B).

Aortic dissection symptoms may be similar to those of other heart problems, such as a heart attack. Typical signs and symptoms include:

• Sudden severe chest or upper back pain, often described as a tearing or ripping sensation, that spreads to the neck or down the back
• Sudden severe stomach pain
• Loss of consciousness
• Shortness of breath
• Symptoms similar to those of a stroke, including sudden vision problems, difficulty speaking, and weakness or loss of movement (paralysis) on one side of your body
• Weak pulse in one arm or thigh compared with the other
• Leg pain
• Difficulty walking

Many of the factors that are known to cause an aortic aneurysm formation may also lead to an aortic dissection.

An aortic dissection that persists for more than two weeks is classified as chronic. It is most commonly found in patients with Type B aortic dissection. If untreated, it may lead to aneurysm formation.

An aortic dissection is a medical emergency requiring immediate treatment. Treatment may include surgery or medications, depending on the area of the aorta involved.

Type A aortic dissection

Treatment for type A aortic dissection may include:

• Surgery. As much as posible of the dissected aorta is removed to stop blood from leaking into the aortic wall. A synthetic tube (graft) is used to reconstruct the aorta. If the aortic valve leaks as a result of the damaged aorta, it may be replaced at the same time. The new valve is placed within the graft.
• Medications. Medications are given to reduce heart rate and lower blood pressure, which can prevent the aortic dissection from worsening. They may be given to people with type A aortic dissection to control blood pressure before surgery.

Type B aortic dissection

Treatment of type B aortic dissection may include:

• Medications. The same medications that are used to treat type A aortic dissection may be used without surgery to treat type B aortic dissections.
• Surgery. The procedure is similar to that used to correct a type A aortic dissection. Sometimes stents — small wire mesh tubes that act as a sort of scaffolding — may be placed in the aorta to repair complicated type B aortic dissections.